Neurostimulation, i.e., neuromuscular stimulation (the electrical excitation of nerves and/or muscle to directly elicit the contraction of muscles) and neuromodulation stimulation (the electrical excitation of nerves, often afferent nerves, to indirectly affect the stability or performance of a physiological system) and brain stimulation (the stimulation of cerebral or other central nervous system tissue) can provide functional and/or therapeutic outcomes. While existing systems and methods can provide remarkable benefits to individuals requiring neurostimulation, many quality of life issues still remain. For example, existing systems perform a single, dedicated stimulation function, and are unable to operate in a fashion to provide coordinated stimulation to multiple regions of a body. Furthermore, these controllers are, by today's standards, relatively large and awkward to manipulate and transport.
There exist both external and implantable devices for providing neurostimulation in diverse therapeutic and functional restoration indications. These neurostimulators are able to provide treatment therapy to individual portions of the body. The operation of these devices typically includes the use of an electrode placed either on the external surface of the skin and/or a surgically implanted electrode. In the case of external neurostimulators, surface electrodes and/or percutaneous lead(s) having one or more electrodes are used to deliver electrical stimulation to the select portion(s) of the patient's body.
Several clinical and technical issues associated with surface electrical stimulation have prevented it from becoming a widely accepted treatment method. First, stimulation of cutaneous pain receptors cannot be avoided resulting in stimulation-induced pain that limits patient tolerance and compliance. Second, electrical stimulation is delivered at a relatively high frequency to prevent stimulation-induced pain, which leads to early onset of muscle fatigue. Third, it is difficult to stimulate deep muscles with surface electrodes without stimulating overlying, more superficial muscles resulting in unwanted stimulation. Finally, clinical skill and intensive patient training is required to place surface electrodes reliably on a daily basis and adjust stimulation parameters to provide optimal treatment. The required daily maintenance and adjustment of a surface electrical stimulation system is a major burden on both patient and caregiver.
It is time that systems and methods for providing neurostimulation address not only specific prosthetic, functional, or therapeutic objections, but also address the quality of life of the individual requiring neurostimulation, including the ability to operate a neurostimulation device without concern for replenishing a power source, and to provide coordinated stimulation to multiple regions of a body.